/*
 * INET		An implementation of the TCP/IP protocol suite for the LINUX
 *		operating system.  INET is implemented using the  BSD Socket
 *		interface as the means of communication with the user level.
 *
 *		The IP to API glue.
 *		
 * Version:	$Id: ip_sockglue.c,v 1.1.1.1 2003/01/15 06:52:58 root Exp $
 *
 * Authors:	see ip.c
 *
 * Fixes:
 *		Many		:	Split from ip.c , see ip.c for history.
 *		Martin Mares	:	TOS setting fixed.
 *		Alan Cox	:	Fixed a couple of oopses in Martin's 
 *					TOS tweaks.
 *		Mike McLagan	:	Routing by source
 */

#if 0

#include <linux/config.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/skbuff.h>
#include <linux/ip.h>
#include <linux/icmp.h>
#include <linux/netdevice.h>
#include <net/sock.h>
#include <net/ip.h>
#include <net/icmp.h>
#include <net/tcp.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/igmp.h>
#include <linux/netfilter.h>
#include <linux/route.h>
#include <linux/mroute.h>
#include <net/route.h>
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
#include <net/transp_v6.h>
#endif

#include <linux/errqueue.h>
#include <asm/uaccess.h>

#else

#include "fake-linux.h"
extern void *memcpy(void *dest, const void *src, size_t n);
extern void *memset(void *s, int c, size_t n);

#endif

#define MAX(a,b) ((a)>(b)?(a):(b))

#define IP_CMSG_PKTINFO		1
#define IP_CMSG_TTL		2
#define IP_CMSG_TOS		4
#define IP_CMSG_RECVOPTS	8
#define IP_CMSG_RETOPTS		16

/*
 *	SOL_IP control messages.
 */

static void ip_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
{
    struct in_pktinfo info;
    struct rtable *rt = (struct rtable *)skb->dst;

    info.ipi_addr.s_addr = skb->nh.iph->daddr;
    if (rt) {
	info.ipi_ifindex = rt->rt_iif;
	info.ipi_spec_dst.s_addr = rt->rt_spec_dst;
    } else {
	info.ipi_ifindex = 0;
	info.ipi_spec_dst.s_addr = 0;
    }

    put_cmsg(msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
}

static void ip_cmsg_recv_ttl(struct msghdr *msg, struct sk_buff *skb)
{
    int ttl = skb->nh.iph->ttl;
    put_cmsg(msg, SOL_IP, IP_TTL, sizeof(int), &ttl);
}

static void ip_cmsg_recv_tos(struct msghdr *msg, struct sk_buff *skb)
{
    put_cmsg(msg, SOL_IP, IP_TOS, 1, &skb->nh.iph->tos);
}

static void ip_cmsg_recv_opts(struct msghdr *msg, struct sk_buff *skb)
{
    if (IPCB(skb)->opt.optlen == 0)
	return;

    put_cmsg(msg, SOL_IP, IP_RECVOPTS, IPCB(skb)->opt.optlen, skb->nh.iph+1);
}


void ip_cmsg_recv_retopts(struct msghdr *msg, struct sk_buff *skb)
{
    unsigned char optbuf[sizeof(struct ip_options) + 40];
    struct ip_options * opt = (struct ip_options*)optbuf;

    if (IPCB(skb)->opt.optlen == 0)
	return;

    if (ip_options_echo(opt, skb)) {
	msg->msg_flags |= MSG_CTRUNC;
	return;
    }
    ip_options_undo(opt);

    put_cmsg(msg, SOL_IP, IP_RETOPTS, opt->optlen, opt->__data);
}


void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
{
    unsigned flags = skb->sk->protinfo.af_inet.cmsg_flags;

    /* Ordered by supposed usage frequency */
    if (flags & 1)
	ip_cmsg_recv_pktinfo(msg, skb);
    if ((flags>>=1) == 0)
	return;

    if (flags & 1)
	ip_cmsg_recv_ttl(msg, skb);
    if ((flags>>=1) == 0)
	return;

    if (flags & 1)
	ip_cmsg_recv_tos(msg, skb);
    if ((flags>>=1) == 0)
	return;

    if (flags & 1)
	ip_cmsg_recv_opts(msg, skb);
    if ((flags>>=1) == 0)
	return;

    if (flags & 1)
	ip_cmsg_recv_retopts(msg, skb);
}

int ip_cmsg_send(struct msghdr *msg, struct ipcm_cookie *ipc)
{
    int err;
    struct cmsghdr *cmsg;

    for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
	if (cmsg->cmsg_len < sizeof(struct cmsghdr) ||
	    (unsigned long)(((char*)cmsg - (char*)msg->msg_control)
			    + cmsg->cmsg_len) > msg->msg_controllen) {
	    return -EINVAL;
	}
	if (cmsg->cmsg_level != SOL_IP)
	    continue;
	switch (cmsg->cmsg_type) {
	case IP_RETOPTS:
	    err = cmsg->cmsg_len - CMSG_ALIGN(sizeof(struct cmsghdr));
	    err = ip_options_get(&ipc->opt, (unsigned char*)CMSG_DATA(cmsg), err < 40 ? err : 40, 0);
	    if (err)
		return err;
	    break;
	case IP_PKTINFO:
	{
	    struct in_pktinfo *info;
	    if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct in_pktinfo)))
		return -EINVAL;
	    info = (struct in_pktinfo *)CMSG_DATA(cmsg);
	    ipc->oif = info->ipi_ifindex;
	    ipc->addr = info->ipi_spec_dst.s_addr;
	    break;
	}
	default:
	    return -EINVAL;
	}
    }
    return 0;
}


/* Special input handler for packets catched by router alert option.
   They are selected only by protocol field, and then processed likely
   local ones; but only if someone wants them! Otherwise, router
   not running rsvpd will kill RSVP.

   It is user level problem, what it will make with them.
   I have no idea, how it will masquearde or NAT them (it is joke, joke :-)),
   but receiver should be enough clever f.e. to forward mtrace requests,
   sent to multicast group to reach destination designated router.
 */
struct ip_ra_chain *ip_ra_chain;
rwlock_t ip_ra_lock = RW_LOCK_UNLOCKED;

int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *))
{
    struct ip_ra_chain *ra, *new_ra, **rap;

    if (sk->type != SOCK_RAW || sk->num == IPPROTO_RAW)
	return -EINVAL;

    new_ra = (struct ip_ra_chain *)(on ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL);

    write_lock_bh(&ip_ra_lock);
    for (rap = &ip_ra_chain; (ra=*rap) != NULL; rap = &ra->next) {
	if (ra->sk == sk) {
	    if (on) {
		write_unlock_bh(&ip_ra_lock);
		if (new_ra)
		    kfree(new_ra);
		return -EADDRINUSE;
	    }
	    *rap = ra->next;
	    write_unlock_bh(&ip_ra_lock);

	    if (ra->destructor)
		ra->destructor(sk);
	    sock_put(sk);
	    kfree(ra);
	    return 0;
	}
    }
    if (new_ra == NULL) {
	write_unlock_bh(&ip_ra_lock);
	return -ENOBUFS;
    }
    new_ra->sk = sk;
    new_ra->destructor = destructor;

    new_ra->next = ra;
    *rap = new_ra;
    sock_hold(sk);
    write_unlock_bh(&ip_ra_lock);

    return 0;
}

void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, 
		   u16 port, u32 info, u8 *payload)
{
    struct sock_exterr_skb *serr;

    panic("ip_icmp_error: sort out sk_buff handling XXX KAF");
#if 0

    if (!sk->protinfo.af_inet.recverr)
	return;

    skb = skb_clone(skb, GFP_ATOMIC);
    if (!skb)
	return;

    serr = SKB_EXT_ERR(skb);  
    serr->ee.ee_errno = err;
    serr->ee.ee_origin = SO_EE_ORIGIN_ICMP;
    serr->ee.ee_type = skb->h.icmph->type; 
    serr->ee.ee_code = skb->h.icmph->code;
    serr->ee.ee_pad = 0;
    serr->ee.ee_info = info;
    serr->ee.ee_data = 0;
    serr->addr_offset = (u8*)&(((struct iphdr*)(skb->h.icmph+1))->daddr) - skb->nh.raw;
    serr->port = port;

    skb->h.raw = payload;
    skb_pull(skb, payload - skb->data);

    if (sock_queue_err_skb(sk, skb))
	kfree_skb(skb);
#endif
}

void ip_local_error(struct sock *sk, int err, u32 daddr, u16 port, u32 info)
{
    struct sock_exterr_skb *serr;
    struct iphdr *iph;
    struct sk_buff *skb;

    if (!sk->protinfo.af_inet.recverr)
	return;

    skb = alloc_skb(sk, sizeof(struct iphdr));
    if (!skb)
	return;

    iph = (struct iphdr*)skb_put_h(skb, sizeof(struct iphdr));
    skb->nh.iph = iph;
    iph->daddr = daddr;

    serr = SKB_EXT_ERR(skb);  
    serr->ee.ee_errno = err;
    serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
    serr->ee.ee_type = 0; 
    serr->ee.ee_code = 0;
    serr->ee.ee_pad = 0;
    serr->ee.ee_info = info;
    serr->ee.ee_data = 0;
    serr->addr_offset = (u8*)&iph->daddr - skb->nh.raw;
    serr->port = port;

    skb->h.raw = skb->h_tail;
    skb_pull_h(skb, skb->h_tail - skb->h_data); // XXX KAF: ??? why?

    if (sock_queue_err_skb(sk, skb))
	kfree_skb(skb);
}

/* 
 *	Handle MSG_ERRQUEUE
 */
int ip_recv_error(struct sock *sk, struct msghdr *msg, int len)
{
    struct sock_exterr_skb *serr;
    struct sk_buff *skb, *skb2;
    struct sockaddr_in *sin;
    struct {
	struct sock_extended_err ee;
	struct sockaddr_in	 offender;
    } errhdr;
    int err;
    int copied;

    err = -EAGAIN;
    skb = skb_dequeue(&sk->error_queue);
    if (skb == NULL)
	goto out;

    copied = skb->len;
    if (copied > len) {
	msg->msg_flags |= MSG_TRUNC;
	copied = len;
    }
    err = memcpy_toiovec(msg->msg_iov, skb->d_data, copied);
    if (err)
	goto out_free_skb;

    serr = SKB_EXT_ERR(skb);

    sin = (struct sockaddr_in *)msg->msg_name;
    if (sin) {
	sin->sin_family = AF_INET; 
	sin->sin_addr.s_addr = *(u32*)(skb->nh.raw + serr->addr_offset);
	sin->sin_port = serr->port; 
    }

    memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
    sin = &errhdr.offender;
    sin->sin_family = AF_UNSPEC;
    if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP) {
	sin->sin_family = AF_INET;
	sin->sin_addr.s_addr = skb->nh.iph->saddr;
	if (sk->protinfo.af_inet.cmsg_flags)
	    ip_cmsg_recv(msg, skb);
    }

    put_cmsg(msg, SOL_IP, IP_RECVERR, sizeof(errhdr), &errhdr);

    /* Now we could try to dump offended packet options */

    msg->msg_flags |= MSG_ERRQUEUE;
    err = copied;

    /* Reset and regenerate socket error */
    sk->err = 0;
    if ((skb2 = skb_peek(&sk->error_queue)) != NULL) {
	sk->err = SKB_EXT_ERR(skb2)->ee.ee_errno;
	sk->error_report(sk);
    }

 out_free_skb:	
    kfree_skb(skb);
 out:
    return err;
}


/*
 *	Socket option code for IP. This is the end of the line after any TCP,UDP etc options on
 *	an IP socket.
 *
 *	We implement IP_TOS (type of service), IP_TTL (time to live).
 */

int ip_setsockopt(struct sock *sk, int level, int optname, char *optval, int optlen)
{
    int val=0,err;

    if(optlen>=sizeof(int)) {
	if(get_user(val, (int *) optval))
	    return -EFAULT;
    } else if(optlen>=sizeof(char)) {
	unsigned char ucval;
	if(get_user(ucval, (unsigned char *) optval))
	    return -EFAULT;
	val = (int)ucval;
    }
    /* If optlen==0, it is equivalent to val == 0 */
	
    if(level!=SOL_IP)
	return -ENOPROTOOPT;
#ifdef CONFIG_IP_MROUTE
    if(optname>=MRT_BASE && optname <=MRT_BASE+10)
    {
	return ip_mroute_setsockopt(sk,optname,optval,optlen);
    }
#endif

    err = 0;
    lock_sock(sk);

    switch(optname)
    {
    case IP_OPTIONS:
    {
	struct ip_options * opt = NULL;
	if (optlen > 40 || optlen < 0)
	    goto e_inval;
	err = ip_options_get(&opt, (unsigned char*)optval, optlen, 1);
	if (err)
	    break;
	if (sk->type == SOCK_STREAM) {
	    struct tcp_opt *tp = &sk->tp_pinfo.af_tcp;
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
	    if (sk->family == PF_INET ||
		((tcp_connected(sk->state) || sk->state == TCP_SYN_SENT)
		 && sk->daddr != LOOPBACK4_IPV6)) {
#endif
		if (opt)
		    tp->ext_header_len = opt->optlen;
		tcp_sync_mss(sk, tp->pmtu_cookie);
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
	    }
#endif
	}
	opt = xchg(&sk->protinfo.af_inet.opt, opt);
	if (opt)
	    kfree_s(opt, sizeof(struct ip_options) + opt->optlen);
	break;
    }
    case IP_PKTINFO:
	if (val)
	    sk->protinfo.af_inet.cmsg_flags |= IP_CMSG_PKTINFO;
	else
	    sk->protinfo.af_inet.cmsg_flags &= ~IP_CMSG_PKTINFO;
	break;
    case IP_RECVTTL:
	if (val)
	    sk->protinfo.af_inet.cmsg_flags |=  IP_CMSG_TTL;
	else
	    sk->protinfo.af_inet.cmsg_flags &= ~IP_CMSG_TTL;
	break;
    case IP_RECVTOS:
	if (val)
	    sk->protinfo.af_inet.cmsg_flags |=  IP_CMSG_TOS;
	else
	    sk->protinfo.af_inet.cmsg_flags &= ~IP_CMSG_TOS;
	break;
    case IP_RECVOPTS:
	if (val)
	    sk->protinfo.af_inet.cmsg_flags |=  IP_CMSG_RECVOPTS;
	else
	    sk->protinfo.af_inet.cmsg_flags &= ~IP_CMSG_RECVOPTS;
	break;
    case IP_RETOPTS:
	if (val)
	    sk->protinfo.af_inet.cmsg_flags |= IP_CMSG_RETOPTS;
	else
	    sk->protinfo.af_inet.cmsg_flags &= ~IP_CMSG_RETOPTS;
	break;
    case IP_TOS:	/* This sets both TOS and Precedence */
#ifndef XXX_KAF_CHANGED
	return(-EINVAL);
#else
	/* Reject setting of unused bits */
	if (val & ~(IPTOS_TOS_MASK|IPTOS_PREC_MASK))
	    goto e_inval;
	if (IPTOS_PREC(val) >= IPTOS_PREC_CRITIC_ECP && 
	    !capable(CAP_NET_ADMIN)) {
	    err = -EPERM;
	    break;
	}
	if (sk->protinfo.af_inet.tos != val) {
	    sk->protinfo.af_inet.tos=val;
	    sk->priority = rt_tos2priority(val);
	    sk_dst_reset(sk); 
	}
#endif
	break;
    case IP_TTL:
	if (optlen<1)
	    goto e_inval;
	if(val==-1)
	    val = ip_statistics.IpDefaultTTL;
	if(val<1||val>255)
	    goto e_inval;
	sk->protinfo.af_inet.ttl=val;
	break;
    case IP_HDRINCL:
	if(sk->type!=SOCK_RAW) {
	    err = -ENOPROTOOPT;
	    break;
	}
	sk->protinfo.af_inet.hdrincl=val?1:0;
	break;
    case IP_MTU_DISCOVER:
	if (val<0 || val>2)
	    goto e_inval;
	sk->protinfo.af_inet.pmtudisc = val;
	break;
    case IP_RECVERR:
	sk->protinfo.af_inet.recverr = !!val;
	if (!val)
	    skb_queue_purge(&sk->error_queue);
	break;
    case IP_MULTICAST_TTL:
	if (sk->type == SOCK_STREAM)
	    goto e_inval;
	if (optlen<1)
	    goto e_inval;
	if (val==-1)
	    val = 1;
	if (val < 0 || val > 255)
	    goto e_inval;
	sk->protinfo.af_inet.mc_ttl=val;
	break;
    case IP_MULTICAST_LOOP: 
	if (optlen<1)
	    goto e_inval;
	sk->protinfo.af_inet.mc_loop = val ? 1 : 0;
	break;
    case IP_MULTICAST_IF: 
    {
	struct ip_mreqn mreq;
	struct net_device *dev = NULL;

	if (sk->type == SOCK_STREAM)
	    goto e_inval;
	/*
	 *	Check the arguments are allowable
	 */

	err = -EFAULT;
	if (optlen >= sizeof(struct ip_mreqn)) {
	    if (copy_from_user(&mreq,optval,sizeof(mreq)))
		break;
	} else {
	    memset(&mreq, 0, sizeof(mreq));
	    if (optlen >= sizeof(struct in_addr) &&
		copy_from_user(&mreq.imr_address,optval,sizeof(struct in_addr)))
		break;
	}

	if (!mreq.imr_ifindex) {
	    if (mreq.imr_address.s_addr == INADDR_ANY) {
		sk->protinfo.af_inet.mc_index = 0;
		sk->protinfo.af_inet.mc_addr  = 0;
		err = 0;
		break;
	    }
	    dev = (struct net_device *)ip_dev_find(mreq.imr_address.s_addr);
	    if (dev) {
		mreq.imr_ifindex = dev->ifindex;
		dev_put(dev);
	    }
	} else
	    dev = (struct net_device *)__dev_get_by_index(mreq.imr_ifindex);


	err = -EADDRNOTAVAIL;
	if (!dev)
	    break;

	err = -EINVAL;
	if (sk->bound_dev_if && mreq.imr_ifindex != sk->bound_dev_if)
	    break;

	sk->protinfo.af_inet.mc_index = mreq.imr_ifindex;
	sk->protinfo.af_inet.mc_addr  = mreq.imr_address.s_addr;
	err = 0;
	break;
    }

    case IP_ADD_MEMBERSHIP:
    case IP_DROP_MEMBERSHIP: 
    {
	struct ip_mreqn mreq;

	if (optlen < sizeof(struct ip_mreq))
	    goto e_inval;
	err = -EFAULT;
	if (optlen >= sizeof(struct ip_mreqn)) {
	    if(copy_from_user(&mreq,optval,sizeof(mreq)))
		break;
	} else {
	    memset(&mreq, 0, sizeof(mreq));
	    if (copy_from_user(&mreq,optval,sizeof(struct ip_mreq)))
		break; 
	}

	if (optname == IP_ADD_MEMBERSHIP)
	    err = ip_mc_join_group(sk,&mreq);
	else
	    err = ip_mc_leave_group(sk,&mreq);
	break;
    }
    case IP_ROUTER_ALERT:	
	err = ip_ra_control(sk, val ? 1 : 0, NULL);
	break;
 
    default:
#ifdef CONFIG_NETFILTER
	err = nf_setsockopt(sk, PF_INET, optname, optval, 
			    optlen);
#else
	err = -ENOPROTOOPT;
#endif
	break;
    }
    release_sock(sk);
    return err;

 e_inval:
    release_sock(sk);
    return -EINVAL;
}

/*
 *	Get the options. Note for future reference. The GET of IP options gets the
 *	_received_ ones. The set sets the _sent_ ones.
 */

int ip_getsockopt(struct sock *sk, int level, int optname, char *optval, int *optlen)
{
    int val;
    int len;
	
    if(level!=SOL_IP)
	return -EOPNOTSUPP;

#ifdef CONFIG_IP_MROUTE
    if(optname>=MRT_BASE && optname <=MRT_BASE+10)
    {
	return ip_mroute_getsockopt(sk,optname,optval,optlen);
    }
#endif

    if(get_user(len,optlen))
	return -EFAULT;

    lock_sock(sk);

    switch(optname)	{
    case IP_OPTIONS:
    {
	unsigned char optbuf[sizeof(struct ip_options)+40];
	struct ip_options * opt = (struct ip_options*)optbuf;
	opt->optlen = 0;
	if (sk->protinfo.af_inet.opt)
	    memcpy(optbuf, sk->protinfo.af_inet.opt,
		   sizeof(struct ip_options)+
		   sk->protinfo.af_inet.opt->optlen);
	release_sock(sk);

	if (opt->optlen == 0) 
	    return put_user(0, optlen);

	ip_options_undo(opt);

	len=min(len, opt->optlen);
	if(put_user(len, optlen))
	    return -EFAULT;
	if(copy_to_user(optval, opt->__data, len))
	    return -EFAULT;
	return 0;
    }
    case IP_PKTINFO:
	val = (sk->protinfo.af_inet.cmsg_flags & IP_CMSG_PKTINFO) != 0;
	break;
    case IP_RECVTTL:
	val = (sk->protinfo.af_inet.cmsg_flags & IP_CMSG_TTL) != 0;
	break;
    case IP_RECVTOS:
	val = (sk->protinfo.af_inet.cmsg_flags & IP_CMSG_TOS) != 0;
	break;
    case IP_RECVOPTS:
	val = (sk->protinfo.af_inet.cmsg_flags & IP_CMSG_RECVOPTS) != 0;
	break;
    case IP_RETOPTS:
	val = (sk->protinfo.af_inet.cmsg_flags & IP_CMSG_RETOPTS) != 0;
	break;
    case IP_TOS:
	val=sk->protinfo.af_inet.tos;
	break;
    case IP_TTL:
	val=sk->protinfo.af_inet.ttl;
	break;
    case IP_HDRINCL:
	val=sk->protinfo.af_inet.hdrincl;
	break;
    case IP_MTU_DISCOVER:
	val=sk->protinfo.af_inet.pmtudisc;
	break;
    case IP_MTU:
    {
	struct dst_entry *dst;
	val = 0;
	dst = sk_dst_get(sk);
	if (dst) {
	    val = dst->pmtu;
	    dst_release(dst);
	}
	if (!val) {
	    release_sock(sk);
	    return -ENOTCONN;
	}
	break;
    }
    case IP_RECVERR:
	val=sk->protinfo.af_inet.recverr;
	break;
    case IP_MULTICAST_TTL:
	val=sk->protinfo.af_inet.mc_ttl;
	break;
    case IP_MULTICAST_LOOP:
	val=sk->protinfo.af_inet.mc_loop;
	break;
    case IP_MULTICAST_IF:
    {
	struct ip_mreqn mreq;
	len = min(len,sizeof(struct ip_mreqn));
	mreq.imr_ifindex = sk->protinfo.af_inet.mc_index;
	mreq.imr_address.s_addr = sk->protinfo.af_inet.mc_addr;
	mreq.imr_multiaddr.s_addr = 0;
	release_sock(sk);

	if(put_user(len, optlen))
	    return -EFAULT;
	if(copy_to_user((void *)optval, &mreq, len))
	    return -EFAULT;
	return 0;
    }
    case IP_PKTOPTIONS:		
    {
	struct msghdr msg;

	release_sock(sk);

	if (sk->type != SOCK_STREAM)
	    return -ENOPROTOOPT;

	msg.msg_control = optval;
	msg.msg_controllen = len;
	msg.msg_flags = 0;

	if (sk->protinfo.af_inet.cmsg_flags&IP_CMSG_PKTINFO) {
	    struct in_pktinfo info;

	    info.ipi_addr.s_addr = sk->rcv_saddr;
	    info.ipi_spec_dst.s_addr = sk->rcv_saddr;
	    info.ipi_ifindex = sk->protinfo.af_inet.mc_index;
	    put_cmsg(&msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
	}
	if (sk->protinfo.af_inet.cmsg_flags&IP_CMSG_TTL) {
	    int hlim = sk->protinfo.af_inet.mc_ttl;
	    put_cmsg(&msg, SOL_IP, IP_TTL, sizeof(hlim), &hlim);
	}
	len -= msg.msg_controllen;
	return put_user(len, optlen);
    }
    default:
#ifdef CONFIG_NETFILTER
	val = nf_getsockopt(sk, PF_INET, optname, optval, 
			    &len);
	release_sock(sk);
	if (val >= 0)
	    val = put_user(len, optlen);
	return val;
#else
	release_sock(sk);
	return -ENOPROTOOPT;
#endif
    }
    release_sock(sk);
	
    if (len < sizeof(int) && len > 0 && val>=0 && val<255) {
	unsigned char ucval = (unsigned char)val;
	len = 1;
	if(put_user(len, optlen))
	    return -EFAULT;
	if(copy_to_user(optval,&ucval,1))
	    return -EFAULT;
    } else {
	len=min(sizeof(int),len);
	if(put_user(len, optlen))
	    return -EFAULT;
	if(copy_to_user(optval,&val,len))
	    return -EFAULT;
    }
    return 0;
}
